I can't imagine ever playing The Sims without CC. I have made the switch to using Maxis Match CC as much as possible versus alpha, but that's as close as I'm ever likely to get. Going vanilla isn't wrong, it's just not my thing.
Mods are another story. Far too many of them are there only to stop a game feature that is out of control, buggy, outright broken, or to add something that the game lacks. I had very few mods for TS3, but I've needed a lot for TS4. The big ones I have that add gameplay I don't mind, the devs can't possibly put every gameplay feature anybody could ever want into the game. There are far too many possibilities. What I wish I didn't need were the ones that stop the game from doing something that was coded in such a way that it goes way over the top or simply doesn't work.